The diamine 2,2'-bis(4-aminocyclohexyl)propane (PACP) can be made by the reaction of ammonia and 2,2'-bis(4-hydroxycyclohexyl) propane (HBPA) over hydrogenation catalysts. PACP, in combination with diacids, is useful for the production of polyamides. Commercially available PACP supplies and crude amination reaction products contain organic impurities. Often these impurities are chemically and physically similar to the PACP, so that their separation from PACP is no simple matter.